I’ve been wondering what Paul Spudis would have to say about yesterday’s press conference. Well, we need wonder no more:
What’s surprising about this new data is not the presence of water, but its pervasiveness. The published image (above) shows this water to be present from the poles down to about 60° latitude. This area subtends over 10 million square kilometers, or about one-third the surface area of the entire Moon! Although the water appears to be present only in the upper few millimeters of the surface, its total mass could be enormous, greatly exceeding the several hundred million tones estimated to be present as ice in the dark areas of the poles.
As always with good science, the new results raise many more questions than they answer. In part, this is a “chicken or egg” issue – do the newly discovered deposits result from surface alteration by water derived from the polar ice, or do they serve as a source for such deposits? How does water form, move, get destroyed or get cold-trapped on the Moon? What are rates of water deposition and removal? What and where are the ice deposits and how pure might they be? Right now we can only dimly perceive the beginnings of a whole new sub-discipline of lunar studies: polar geoscience.
Lunar geoscience. I guess the battle is lost…
What battle? If you mean the quixotic one against using the prefix “geo-” for lunar science, that battle was lost about 40 years ago, after it was shown that the classic techniques of geological analysis could be profitably applied to the Moon and other bodies.
We wrote a report on the status of Lunar Geoscience back in 1986:
http://www.lpi.usra.edu/lunar_resources/documents/LunarGeoscience.pdf
If they said “selenology”, very few would have understood (alas).
Would you seriously want a different word for the exact same science, except on the moon? “Lunar geoscience” makes a lot more sense than “selenology” or whatever.
How about “rockology?”
Isn’t “rockology” a discipline belonging to the music department?
By the way, according to Merriam-Webster online, the definition of geology is:
1 a : a science that deals with the history of the earth and its life especially as recorded in rocks b : a study of the solid matter of a celestial body (as the moon)
Note definition 1b. I wonder when that was added? I realize that President O doesn’t accept Merriam-Webster as definitive (see definition of “Tax”) but if it’s good enough for George Stephanopoulis, it’s good enough for me.
Somewhat back on topic, what does the discovery of the pervasiveness of water on the Moon mean to manned exploration? If the vast majority of it is in a 3cm later of hoarfrost buried 10′ under the regolith I’d have to say, “Not Much”. Deep frozen lakes of comet-ice in shadowed craters, quite a bit more. Warm inviting oceans with white sand beaches and nubile moon-maidens frolicking in the surf…sign me up.
All this discovery has proven, I gather, is that cosmic rays cause a detectable reaction with hydrogen in the top couple of mm of regolith. I see from the 60º figure above that this hydrogen is far from anywhere a Apollo mission could have measured it, so we don’t know firsthand how far down it goes.
Is the source of this hydrogen solar wind, which could be expected to be only near the surface? Or is there reason to believe it goes down deeper?
I would be quite encouraged if it was a shallow surface layer, as this should be relatively easy to dig up and process. A deep permafrost could be difficult to extract water from.
“A deep permafrost could be difficult to extract water from.”
Do we have enough nitrates to make TNT on the Moon?
IF we have Iron Oxide and Aluminum, we could make thermite and melt it.
All this discovery has proven, I gather, is that cosmic rays cause a detectable reaction with hydrogen in the top couple of mm of regolith.
You are confusing two different things. The “top couple mm” evidence is infrared spectral evidence (for OH). Cosmic rays, on the other hand, make spallation neutrons, and the intensity/energy spectrum of those neutrons is a function of the amount of hydrogen in the top meter or so of the regolith (since hydrogen is very effective at reducing the neutron energy by elastic collisions.)
Mr. Puckett,
Off the top of my head, I think lunar regolith is 13% Al and quite a bit of FeO (and other stuff within ilmenite). Hmmmmmm.
Geoff Landis studied the diffusion of contaminant gases from a lunar base (click on my name for the link), and concluded that oxygen would diffuse all over the moon in about 47 hours, water molecules in a few hours. Since the loss time for water molecules is days to weeks, most of them should get many chances to get cold trapped at the poles long before they can get photoionized and lost.
The mechanism seems (to me) to go like this:
1) Solar protons at > 100 km/s hit the surface, embedding well below the surface of oxide rocks. Yield is 100%
2) The protons pick up an electron, neutralizing to an isolated hyrogen atom. Yield is 100%
3) These hydrogen atoms react with a nearby metal oxide molecule, forming a metal hydroxide. Yield near 100% (?)
4) Some tiny fraction of new hydrogen atoms react with an existing metal hydroxide, forming water. Yield around 10^-6 ? Regolith gets plowed under by impacts long before the surface is saturated with hydroxides, so only a very small fraction of the hydrogen ever gets mobilized by joining a hydroxyl radical.
5) These water molecules eventually escape from the rock, and fly off one at a time. Yield is 100%
6) Mobile water molecules generally get cold trapped before they get ionized by solar UV. Yield is 1-loss, where loss is trap time/loss time, maybe 10 hours/300 hours… so yield is >90%
Overall, a few parts per million of the solar wind protons end up at the poles in cold traps- but with a few billion years of trapping, that can be quite a lot, and we aren’t considering any comet infall water here.
Promising…
Rand,
Also terms like geology, geography, geochemistry honor humanity’s home, the Earth, where the basic principles and concepts of these disciplines were first developed.
Perhaps a thousand years from now in a classroom on a planet orbiting a distant star geology students will pause a moment to remember the emergence of their discipline in the green hills of Victorian England on a planet called Earth.
Tom
Of course, then we would not only have selenology, but aresology, zeusology, and kronosology or (as I prefer to say) saturnalia. 🙂
This also recalls “classic” SF authors who insisted on referring to astrogators instead of navigators. Navigate has long since lost its strict connection to naval course control, and is frequently used for any kind of planned or directed travel, including a robot “navigating” an obstacle course.
If one insists on such purism, I would also suggest attacking those who define gigabyte as 1 billion bytes, actors defining both male and female performers, and female airmen.
Come to think of it, we should return to the Romance-language practice of having masculine and feminine forms of verbs & nouns, and lose the modern English practice of adding a simple “s” to a word for the plural. Brethren is, after all, so much more poetic than brothers, no?
Assuming the discovery of water pans out, any prediction on when we’ll hit “peak water” on the moon? I assume that this is essentially a non-renewable resource over reasonable human time spans. As such is just sitting there for the taking by the person who manages to get there first?
An area the size of the United states of America – it might take a while to process.
I recall reading a “Star Trek” novel by James Blish in which he referred to the “Klingon Space Navy.” Given that in “Star Trek” Chekov was the navigator rather than the “astrogator,” I wonder if Blish was twitting the show’s writers a little there.
Oddly enough, even the TV show “Lost in Space” referred to the computer used for navigation as “the astrogator.” When I first heard that, given the show’s predilections, I expected to see a space alien with the head of a crocodile.
In re: “astrogator”
I seem to recall Robby the Robot taking the “astrogator” role in the last scene of “Forbidden Planet.”
On the same linquistic front, I finally gave up the battle of using planet-specific terms for nearest and farthest approach in an orbit. I was fine with “perigee and apogee”, “perihelion and apohelion”, “periselene and aposelene” (or “pericynthion” in Apollo terms) … but when I started looking at Mars trajectories, I simply gave up at “periareion”.
I fought a holding action with the technically correct “periapsis and apoapsis” for a while, which are the generic terms …. but when “perigee” slips out for a body other than Earth, I no longer worry about it too much.
Release hundreds of thousands of robot bugs onto the surface of the moon and let them scurry around to prep the surface for easier processing of the regolith. Termites after all build massive towering mounds.
Of course there is water on the moon. The moon was made from the Earth when another planet impacted us early on. The debris coalesced and made the moon.Wouldn’t be surprised if they found a dick fossil up there from an early Earth species.